$str="一二三四五ABN420122(电话:123455)";
$reg= '/.*\(.*:(.*)\)/';//冒号和$str保持一致
$reg= '/.*\(.*(\d{6,})\)/';
$reg= '/.*\(.*[^\d](\d+)\)/';
preg_match_all($reg,$str,$want);
print_r($want[1]);
3种正则 都可以
preg_match_all('/(电话:\d*)/i',$str,$str_ary);
如果不想用“电话这种汉字”
preg_match_all("/\((.*\d+)/i",$str,$str_ary);
$str="一二三四五ABN420122(电话:123455)";
preg_match_all("/[^\(]*\(\D*(\d*).*/i",$str,$str_ary);
var_export($str_ary);
exit;
preg_match_all("/(.*)[(](.*)(\d*)[)](.*)/isU", $str, $str_ary);